I'm starting this thread, because we want to build a web application that uses web maps to search for archaeological data - See:
http://www.dana-wh.net

Our big problem right now is that all of our test case data is for American Samoa, and as a depended country, it doesn't show up under Oceania in geotree.

In our Java-based Dana app, we have it listed as:
"Oceania>United States>American Samoa"

Another issue we have is that Hawaii is definitely in Oceania, physically, and culturally, but in geotree it shows up in under the US in North America. Our Dana app has Hawaii listed as:
"Oceania>United States>Hawaii"

Being new to this, I would expect there are good reasons as to why these designations are not possible, but I'd like to start the discussion.

I think getting an idea of what kind of countries we have and how the relations between them should be modeled is the first step and afterwards we can think about how it could be implemented.
Do you want to help with the compilation of the list and make it consistent? Not only for the US but also for other countries like France or the UK.

It sounds as though you are open to being able to add countries to multiple continents. Is there anything I can help with there? I think it makes sense to be able to add the US to Oceania as well as North America... and GB and France to various continents as necessary.

I think that France for instance belongs to Europe. I understand that some dependencies are outside of Europe and this should be reflected somehow. I think most users of GeoNames are mainly interested in the 'main' continent of a country, but we should also be able to include the information how countries may depend on each other. The best will be to keep this information in a separate data set, so that users interested in this information can read the dependency information and build their applications accordingly. The dependency information is not that big, it can easily be cached and be part of the application itself.

or
(Just an example I don't know that the equivalent of states would is in France)
Europe>France>Normandy
Oceania>French Territories>French Polynesia

Though, it still wouldn't address the unique case of Hawaii, and now that I think about it, if a country has territories or dependencies in several continents, then what I just wrote wouldn't work either.

Though, I guess I don't see the problem with having a country display under more than one continent as long the sub-units only show up if they belong in that region as well.

For instance if I check the tree:
Oceania>United States

I would only see:
Hawaii
American Samoa
(etc...)
I wouldn't see North Dakota

And vice versa, only the 49 states (and possibly the Caribbean territories) would show up if I check "North America>United States". Hawaii wouldn't show up as it is actually located in Oceania.